Unsaturated polyester resin, cured product of unsaturated polyester resin, resin composition, and method for producing unsaturated polyester resin

Abstract

To provide an unsaturated polyester resin having a novel structure, exhibiting enhanced compatibility and reactivity with a variety of other polymer materials, and a method for producing the same.SOLUTION: An unsaturated polyester resin includes a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2). (In formula (1), R1 is a divalent connecting group having one or more ethylenically unsaturated bonds). (In formula (2), R2 and R3 are each independently a linear or branched hydrocarbon connecting group having 1 to 10 carbon atoms, and n is the number of repeating units).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to unsaturated polyester resins, cured products of unsaturated polyester resins, resin compositions, methods for producing unsaturated polyester resins, and the like.

Background Art

[0002] Since polyester resins are excellent in mechanical strength, electrical insulation, heat resistance, chemical resistance, etc., they are used in various applications, and various polyester resins, unsaturated polyester resins, and methods for producing them have been reported.

[0003] For example, Patent Document 1 discloses a terminally modified polybutadiene having a novel structure obtained by reacting a terminal hydroxyl group-modified polybutadiene with maleic anhydride or succinic anhydride.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, Patent Document 1 only discloses the synthesis of a terminally modified polybutadiene having a novel structure, and the usefulness of the terminally modified polybutadiene has not been studied at all. In fact, although Patent Document 1 lists additives for various rubbers as intended uses, no specific performance evaluations to prove their usefulness as additives for various rubbers are shown.

[0006] By the way, in recent years, with the expansion of the applications of polymer materials, the required performance has become diversified or sophisticated. For example, in recent applications such as electronic materials, not only electrical properties such as dielectric properties, but also, for example, compatibility, moldability, mechanical strength, low thermal expansion rate, low warpage, metal adhesion, etc. may be required, and it has become difficult to satisfy these required performances with a single polymer. Therefore, polymer blends and polymer alloys have been considered, but polyester resins have poor compatibility and reactivity with various other polymer materials and it has been difficult to obtain the desired performance.

[0007] The present invention has been made in view of the above problems. An object of the present invention is to provide an unsaturated polyester resin having a novel structure and a method for producing the same, in which the compatibility and reactivity with various other polymer materials are enhanced. Another object of the present invention is to provide an unsaturated polyester resin having a novel structure and a method for producing the same, in which the compatibility and reactivity with a curable material used in electronic materials and the like are enhanced.

[0008] Furthermore, another object of the present invention is to provide a resin composition containing an unsaturated polyester resin having a novel structure and a cured product of the unsaturated polyester resin, etc., which can achieve excellent mechanical strength, moldability, surface properties, low thermal expansion rate, dielectric properties, copper foil adhesion, low warpage, etc. when used as a laminate for electronic material applications.

Means for Solving the Problems

[0009] The present inventors earnestly studied by focusing on the structure and composition of polyester resins in order to solve the above problems. As a result, they found that the above problems can be solved by using a polyester resin containing a specific structural unit, and thus completed the present invention.

[0010] The present invention provides various specific embodiments shown below. [1] An unsaturated polyester resin containing a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2). Unsaturated polyester resin. [Chemical formula] (In the above formula (1), R 1 is a divalent linking group having one or more ethylenically unsaturated bonds.) [Chemical formula] (In the above formula (2), R 2 and R 3 are each independently a linear or branched hydrocarbon linking group having 1 to 10 carbon atoms, and n is the number of repeating units.) [2] n in the structural unit represented by the above formula (2) is 5 or more and 33 or less, The unsaturated polyester resin according to [1]. [3] The structural unit represented by the above formula (1) is derived from at least one selected from the group consisting of unsaturated dicarboxylic acids, aromatic dicarboxylic acids, and acid anhydrides thereof, The unsaturated polyester resin according to [1] or [2]. [4] The structural unit represented by the above formula (2) is derived from hydrogenated polybutadiene having terminal hydroxyl groups, The unsaturated polyester resin according to any one of [1] to [3]. [5] The structural unit represented by the above formula (1) is derived from at least one selected from the group consisting of maleic anhydride, maleic acid, fumaric acid, phthalic anhydride, and phthalic acid, The unsaturated polyester resin according to any one of [1] to [4]. [6] The molar ratio of the structural unit represented by the above formula (1) to the structural unit represented by the above formula (2) is 0.50 or more and 5.0 or less, The unsaturated polyester resin according to any one of [1] to [5]. [7] The number average molecular weight is 5.00×10 2 or more and 3.00×10 4 or less, The unsaturated polyester resin according to any one of [1] to [6]. [8] The cured product of the unsaturated polyester resin according to any one of [1] to [7]. [9] A resin composition containing the unsaturated polyester resin according to any one of [1] to [7].

[10] The content of the unsaturated polyester resin is 0.50 parts by mass or more with respect to 100 parts by mass of the resin component. The resin composition according to [9].

[11] A method for producing an unsaturated polyester resin, which includes reacting a compound represented by the following formula (4) and / or a compound represented by the formula (4') with a compound represented by the following formula (5). A method for producing an unsaturated polyester resin.

Chemical formula

Chemical formula

Chemical formula

[12] In the compound represented by the formula (5), n is 5 or more and 33 or less. The production method described in

[11] .

[13] Reacting the compound represented by the formula (4) and / or the compound represented by the formula (4') with the compound represented by the formula (5) such that the molar ratio of the total amount of the compound represented by the formula (4) and the compound represented by the formula (4') to the compound represented by the formula (5) is 0.50 or more and 5.0 or less, The production method described in

[11] . [Advantages of the Invention]

[0011] According to one aspect of the present invention, it is possible to realize an unsaturated polyester resin having a novel structure, a production method thereof, etc., in which the compatibility and reactivity with other various polymer materials are enhanced. Further, according to another aspect of the present invention, it is possible to realize an unsaturated polyester resin having a novel structure, a production method thereof, etc., in which the compatibility and reactivity with a curable material used in electronic materials and the like are enhanced.

[0012] Furthermore, according to another aspect of the present invention, there are provided a resin composition containing an unsaturated polyester resin having a novel structure, a cured product of the unsaturated polyester resin, etc., which can realize excellent mechanical strength, moldability, surface properties, etc. when used as a laminate for electronic material applications. As a result, in a preferred aspect of the present invention, it becomes possible to obtain a resin composition, prepreg, flexible laminate, etc., having a high peel strength of a metal foil with excellent productivity and economy. [Embodiments for Carrying Out the Invention]

[0013] Hereinafter, embodiments of the present invention will be described in detail. However, the embodiments described herein are examples for explaining the present invention, and the present invention is not limited thereto. That is, the technical scope of the present invention should be determined based on the description in the claims, and the present invention can be implemented by arbitrarily changing the following embodiments without departing from the gist thereof. In this specification, for example, the numerical range notation of "1 to 100" includes both the lower limit value "1" and the upper limit value "100". The same applies to the notation of other numerical ranges.

[0014] In this specification, the bond cut by a wavy line in the chemical structural formula means the bonding site to another structural unit in the structural unit represented by each chemical structural formula. Here, as will be described later, the terminal group of the unsaturated polyester resin may remain as a carboxy group and / or a hydroxy group without constituting the above bonding site. Further, as will be described later, the terminal group of the unsaturated polyester resin of the present embodiment may have a structure in which the carboxy group and / or the hydroxy group is blocked by a terminal blocking agent.

[0015] [Unsaturated polyester resin] The unsaturated polyester resin of the present embodiment includes a structural unit represented by the following formula (1) (hereinafter, also referred to as "dicarboxylic acid unit") and [Chemical formula] a structural unit represented by the following formula (2) (hereinafter, also referred to as "dihydroxy unit") and [Chemical formula] and contains. Here, in the above formula (1), R 1 is a divalent linking group having one or more ethylenically unsaturated bonds, and in the above formula (2), R 2 and R 3 are each independently a linear or branched hydrocarbon linking group having 1 to 10 carbon atoms, and n is the number of repeating units.

[0016] Since the unsaturated polyester resin of the present embodiment has a divalent linking group having one or more ethylenically unsaturated bonds in the dicarboxylic acid unit represented by the above formula (1), at least starting from this ethylenically unsaturated bond, it can crosslink intramolecularly or intermolecularly, that is, it can be cured by an appropriate method. Conventional saturated polyester resins that do not have an ethylenically unsaturated bond do not have a point (functional group) that can be crosslinked. Therefore, when added to a compound or resin with low compatibility, problems such as phase separation or peeling at the interface with the compound or resin may occur. Further, although the unsaturated polyester resin of the present embodiment is a resin containing an ester bond, it has one or more ethylenically unsaturated bonds. Therefore, when mixed with other compounds or resins, it can react with the functional groups of the compound or resin and crosslink. As a result, the unsaturated polyester resin of the present embodiment can be cured alone, and further, phase separation and interfacial peeling are less likely to occur even when mixed with other compounds or resins.

[0017] In addition, the unsaturated polyester resin of the present embodiment has the dicarboxylic acid unit represented by the above formula (1) and the dihydroxy unit represented by the above formula (2). In other words, it has not only the ester skeleton of the conventional saturated polyester resin, but also an ethylenically unsaturated bond that functions as a crosslinking point and a hydroxy skeleton (a hydroxy skeleton having a 1,2-butadiene skeleton) in which a linear alkyl group (ethyl group) is introduced into the side chain. Therefore, it is presumed that the compatibility, reactivity, dielectric properties, etc. with various other polymer materials are enhanced as compared with conventional saturated polyester resins that do not have these characteristics. And as a result of these combined, for example, when made into a polymer blend or polymer alloy with various other polymer materials such as maleimide-based resins, the resin composition and cured product exhibit excellent mechanical strength, moldability, surface properties, etc. When these resin compositions and cured products are used as laminates for electronic material applications, etc., it is presumed that the laminates, etc. exhibit excellent mechanical strength, moldability, surface properties, low thermal expansion, low warpage, low crack properties, etc. However, the effects are not limited to these.

[0018] The unsaturated polyester resin of this embodiment is a resin that cures in response to an appropriate stimulus or spontaneously. The unsaturated polyester resin of this embodiment is, in one aspect, a thermosetting resin, and in another aspect, a photocurable resin. As yet another aspect, the unsaturated polyester resin of this embodiment is a thermally and / or photocurable resin.

[0019] R in the dicarboxylic acid unit represented by the above formula (1) 1 is a divalent linking group having one or more ethylenically unsaturated bonds. The unsaturated polyester resin of this embodiment can be crosslinked alone or with a crosslinking agent starting from the ethylenically unsaturated bond. Here, in this specification, the "ethylenically unsaturated bond" means a term that includes both a carbon-carbon double bond (ethylenically unsaturated double bond) and a carbon-carbon triple bond (acetylenically unsaturated triple bond). Therefore, the "divalent linking group having one or more ethylenically unsaturated bonds" includes a divalent linking group having one carbon-carbon double bond, a divalent linking group having two or more carbon-carbon double bonds, a divalent linking group having one carbon-carbon triple bond, and the like. Here, when R 1 has two or more ethylenically unsaturated bonds, the divalent linking group may be a linear, branched, or cyclic divalent linking group. When there are two or more carbon-carbon double bonds, a conjugated double bond may be formed. This means that the divalent linking group having one or more ethylenically unsaturated bonds includes an aromatic ring such as a benzene ring (phenylene skeleton).

[0020] R in the above formula (1) 1 is not particularly limited, but is preferably, for example, a divalent linking group having 2 to 10 carbon atoms, more preferably a divalent linking group having 2 to 8 carbon atoms, still more preferably a divalent linking group having 2 to 6 carbon atoms, and particularly preferably a divalent linking group having 2 or 6 carbon atoms. R in the above formula (1) 1The total number of ethylenically unsaturated bonds it has is not particularly limited as long as it is 1 or more, preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less, and still more preferably 1 or 3. The above R 1 preferably has an ethylenically unsaturated double bond or an aromatic ring such as a benzene ring. In the above formula (1), R 1 In a preferred embodiment, for example, a divalent hydrocarbon group having 2 or more and 4 or less carbon atoms and having one ethylenically unsaturated double bond can be mentioned. Specifically, a methylene group, an ethylene group, and a propane-1,3-diyl group can be mentioned. The above R 1 In another preferred embodiment, for example, a divalent hydrocarbon group having one benzene ring can be mentioned. Specifically, a phenylene group can be mentioned. In this preferred embodiment, the number of ethylenically unsaturated bonds and the number of carbon atoms of R 1 may be arbitrarily replaced within the above preferred ranges.

[0021] In the above formula (1), R 1 When having an ethylenically unsaturated double bond, the isomer structure of R 1 is not particularly limited. That is, the dicarboxylic acid unit represented by the above formula (1) may be in a cis configuration or a trans configuration.

[0022] In the above formula (1), R 1 When having an aromatic ring, the isomer structure of R 1 is not particularly limited. That is, the dicarboxylic acid unit represented by the above formula (1) may be in an ortho configuration, a meta configuration, or a para configuration.

[0023] The dicarboxylic acid unit represented by the above formula (1) is preferably a structural unit represented by the following formula (1-1) or (1-2).

Chemical formula

Chemical formula

[0024] The dicarboxylic acid unit represented by the above formula (1) is preferably a structural unit derived from an unsaturated dicarboxylic acid, an aromatic dicarboxylic acid, and their acid anhydrides. Further, it is particularly preferably a structural unit derived from maleic anhydride, maleic acid, fumaric acid, phthalic anhydride, and phthalic acid, which are the dicarboxylic acid unit anhydrides represented by the above formula (1). In this case, R 1 in the above formula (1) respectively corresponds to a divalent hydrocarbon linking group having 2 carbon atoms with an ethylenically unsaturated double bond or a divalent hydrocarbon linking group having 6 carbon atoms with a benzene ring.

[0025] The unsaturated polyester resin of this embodiment may contain only the dicarboxylic acid unit represented by the above formula (1) as the dicarboxylic acid unit, or may contain a carboxylic acid unit other than the dicarboxylic acid unit represented by the above formula (1) (hereinafter also referred to as "other carboxylic acid unit"). That is, the unsaturated polyester resin of this embodiment may contain only one kind of dicarboxylic acid unit or may contain two or more kinds of dicarboxylic acid units.

[0026] In the dihydroxy unit represented by the above formula (2), R 2 and R 3 are, independently of each other, a linear or branched hydrocarbon linking group having 1 to 10 carbon atoms. The number of carbon atoms in the above R 2 and R 3 is, independently of each other, preferably 1 or more and 6 or less, more preferably 2 or more and 4 or less, and particularly preferably 2 or more and 3 or less. The above R2 and R 3 In a preferred embodiment, for example, it is a linear hydrocarbon linking group having 2 carbon atoms.

[0027] In the above formula (2), n is the number of repeating units and is not particularly limited, but is preferably 5 or more and 33 or less, more preferably 10 or more and 32 or less, still more preferably 15 or more and 31 or less, particularly preferably 20 or more and 30 or less, and most preferably 23 or more and 29 or less. When n in the above formula (2) is within the above preferred numerical range, the molecular weight of the unsaturated polyester resin of the present embodiment obtained does not become too large, and good compatibility, appropriate viscosity, and hydroxyl value can be maintained. As a result, for example, when forming a polymer blend or polymer alloy with various other polymer materials such as maleimide resins, it tends to be possible to maintain good mechanical properties, moldability, surface properties, etc. without excessively impairing the reactivity. The number of repeating units n can be easily known from catalog values or the like when the raw materials can be specified, and the value described in the catalog values or the like is used as the number of repeating units n. If not, for example, when the structure and molecular weight of the raw materials are known, the number of repeating units n can be determined as an average value by calculation based on these. Also, when the structure and molecular weight of the raw materials are unknown, the structure and molecular weight of the raw materials can be specified by known measurement methods such as NMR and GPC.

[0028] The dihydroxy unit represented by the above formula (2) is particularly preferably a structural unit derived from terminal hydroxyl group-containing hydrogenated polybutadiene. Here, "terminal hydroxyl group-containing hydrogenated polybutadiene" is a polybutadiene obtained by hydrogenating the vinyl group of the 1,2-polybutadiene skeleton in the repeating unit of the terminal hydroxyl group-containing polybutadiene represented by the following formula (2-1), and has hydroxyl groups at both ends of the polybutadiene. Here, in the following formula (2-1), R 2 , R 3 , and n have the same meanings as those described in the above formula (2), and R 5 and R 6Each is independently a hydrogen atom. Note that the terminal hydroxyl group-containing hydrogenated polybutadiene may unavoidably contain unreacted vinyl groups remaining without being hydrogenated in the repeating unit.

Chemical formula

[0029] The unsaturated polyester resin of this embodiment may contain only the dihydroxy unit represented by the above formula (2) as the dihydroxy unit, or may contain a dihydroxy unit other than the dihydroxy unit represented by the above formula (1) (hereinafter also referred to as "other dihydroxy unit"). That is, the unsaturated polyester resin of this embodiment may contain only one type of dihydroxy unit, or may contain two or more types of dihydroxy units.

[0030] In addition to the dicarboxylic acid unit represented by the above formula (1) and the dihydroxy unit represented by the above formula (2), the unsaturated polyester resin of this embodiment may contain a further structural unit. Examples of the further structural unit include a structural unit derived from a dicarboxylic acid compound not corresponding to the above formula (1) as another dicarboxylic acid unit, a structural unit derived from a dihydroxy compound not corresponding to the above formula (2) as another dihydroxy unit, a monohydroxy compound having an ethylenically unsaturated bond, and the like.

[0031] The other dicarboxylic acid unit is not particularly limited, and examples thereof include saturated aliphatic dicarboxylic acids and their acid anhydrides. Examples of the saturated aliphatic dicarboxylic acid include cyclohexanedicarboxylic acid, cyclopentanedicarboxylic acid, adipic acid, succinic acid, sebacic acid, alkyl succinic acid, cyclohexane diacetic acid, azelaic acid, malonic acid, dimethyl malonic acid, oxalic acid, and the like.

[0032] The other dihydroxy unit is not particularly limited, and examples thereof include aliphatic dihydroxy compounds and aromatic dihydroxy compounds. Examples of the aliphatic dihydroxy compound include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,4-butenediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 2-ethyl-2-methylpropane-1,3-diol, 2-butyl-2-ethylpropane-1,3-diol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2,4-dimethyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and the like.

[0033] Examples of the aromatic dihydroxy compound include hydroquinone, resorcinol, 4,4'-dihydroxybiphenyl, xylylene glycol, 4,4'-dihydroxydiphenylbenzophenone, bisphenols, and the like.

[0034] Examples of the monohydroxy compound having an ethylenically unsaturated bond include hydroxy group-containing (meth)acrylate esters, specifically, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, and the like.

[0035] In addition, the unsaturated polyester resin of the present embodiment may further include, as a partial structure, a structure derived from a silicone oil having a hydroxy group in the molecular structure, a structure derived from a silicone oil having a carboxy group in the molecular structure, and the like.

[0036] As the silicone oil having a hydroxy group in the molecular structure, commercially available products can be used. For example, "KF-6001" (functional group equivalent 900), "KF-6002" (functional group equivalent 1600) having hydroxy groups at both ends, "X-22-1821" (functional group equivalent 1470) having phenolic hydroxy groups at both ends (manufactured by Shin-Etsu Chemical Co., Ltd. as above), "BY-16-752A" (functional group equivalent 1500) (manufactured by Toray Dow Corning Co., Ltd. as above), "X-22-170BX" (functional group equivalent 2800), "X-22-170DX" (functional group equivalent 4670), "X-22-176DX" (functional group equivalent 1600), "X-22-176F" (functional group equivalent 6300) having a hydroxy group at one end (manufactured by Shin-Etsu Chemical Co., Ltd. as above), "X-22-4039" (functional group equivalent 970), "X-22-4015" (functional group equivalent 1870) having a hydroxy group in the side chain (manufactured by Shin-Etsu Chemical Co., Ltd. as above), "SF8427" (functional group equivalent 930, manufactured by Toray Dow Corning Co., Ltd.) and "X-22-4952" (functional group equivalent 1100, manufactured by Shin-Etsu Chemical Co., Ltd.) having a hydroxy group in the polyether at both ends; "FZ-2162" (functional group equivalent 750) and "SH3773M" (functional group equivalent 800) (manufactured by Toray Dow Corning Co., Ltd. as above) having a hydroxy group in the side chain polyether, etc. can be mentioned.

[0037] Also, as the silicone oil having a carboxy group in the molecular structure, commercially available products can be used. For example, "X-22-162C" (functional group equivalent 2300) having carboxy groups at both ends, "X-22-3710" (functional group equivalent 1450) having a carboxy group at one end, and "X-22-3701E" (functional group equivalent 4000) having a carboxy group in the side chain (manufactured by Shin-Etsu Chemical Co., Ltd. as above), etc. can be mentioned.

[0038] By introducing the above-mentioned further structural units and / or further partial structures into the unsaturated polyester resin of this embodiment, there is a tendency to improve or impart properties such as flexibility, mechanical strength, heat resistance, flame retardancy, color tone, and solvent solubility.

[0039] The unsaturated polyester resin of the present embodiment may contain the above-described further structural units and / or further partial structures, either one alone or two or more in any combination and ratio.

[0040] The terminal groups of the unsaturated polyester resin of the present embodiment may be, for example, carboxy groups and / or hydroxy groups without constituting the bonding sites cut by the wavy lines in the above formulas (1) and (2). The terminal groups of the unsaturated polyester resin of the present embodiment preferably have a structure in which the carboxy groups and / or hydroxy groups are blocked by a terminal blocking agent. The terminal carboxy group blocking agent is not particularly limited as long as it is a compound having a group that reacts with a carboxy group, and examples thereof include carbodiimide compounds such as monocarboxydiimide and polycarboxydiimide compounds, oxazoline compounds, and mono-terminal diols. Examples of the terminal hydroxy group blocking agent include diphenyl carbonate and monocarboxylic acid.

[0041] In the unsaturated polyester resin of the present embodiment, it is preferable that the dicarboxylic acid unit represented by the above formula (1) and the dihydroxy unit represented by the above formula (2) are adjacent to each other to form an ester bond. Here, in the unsaturated polyester resin, the oxygen atoms possessed by these units at both ends are shared with adjacent units. That is, when these form an ester bond, the unsaturated polyester resin of the present embodiment contains a structural unit represented by the following (3) by the esterification reaction of dicarboxylic acids and diols, which are the raw materials of both units.

Chemical formula

[0042] In the unsaturated polyester resin of the present embodiment, the molar ratio of the dicarboxylic acid unit represented by the above formula (1) to the dihydroxy unit represented by the above formula (2) is not particularly limited, but is preferably 0.50 or more and 5.0 or less, more preferably 0.60 or more and 3.0 or less, still more preferably 0.70 or more and 2.0 or less, and particularly preferably 0.75 or more and 1.50 or less. The ratio of the dicarboxylic acid unit represented by the above formula (1) and the ratio of the dihydroxy unit represented by the above formula (2) in the unsaturated polyester resin of the present embodiment can be measured by a nuclear magnetic resonance apparatus (NMR).

[0043] In the unsaturated polyester resin of the present embodiment, the total content N of the dihydroxy units OH to the total content N of the dicarboxylic acid units COOH The molar ratio N COOH / N OH is not particularly limited, but is preferably 0.50 or more and 5.0 or less, more preferably 0.60 or more and 3.0 or less, still more preferably 0.70 or more and 2.0 or less, and particularly preferably 0.75 or more and 1.50 or less. The above molar ratio N COOH / N OH can be measured by a nuclear magnetic resonance apparatus (NMR).

[0044] From the viewpoint of further improving the solvent solubility, bleed-out resistance, copper foil adhesion, etc. of the unsaturated polyester resin, in the unsaturated polyester resin of the present embodiment, among all the structural units derived from the dicarboxylic acid compound, the ratio of the dicarboxylic acid unit represented by the above formula (1) is preferably 0.60 or more, more preferably 0.70 or more, still more preferably 0.80 or more, and particularly preferably 0.90 or more in terms of molar ratio. The upper limit value of the ratio is not particularly limited, but may be, for example, 1.0, 0.98, or 0.96. From the same perspective, in the unsaturated polyester resin of the present embodiment, among all the structural units derived from the dihydroxy compound, the proportion of the dihydroxy units represented by the above formula (2) is preferably 0.60 or more, more preferably 0.70 or more, still more preferably 0.80 or more, and even more preferably 0.90 or more in terms of molar ratio. The upper limit value of the proportion is not particularly limited, and for example, it may be 1.0, 0.98, or 0.96.

[0045] Note that the content of the structural units derived from each monomer can be controlled by adjusting the charged amount (usage amount) of each monomer in the production of the unsaturated polyester resin. In this case, for monomers that are likely to evaporate and flow out of the system, it is preferable to use more of them than monomers that are less likely to evaporate in consideration of the outflow to the outside of the system.

[0046] The number average molecular weight of the unsaturated polyester resin of the present embodiment is not particularly limited, but is preferably 5.00×10 2 or more and 3.00×10 4 or less, more preferably 1.00×10 3 or more and 2.00×10 4 or less, still more preferably 1.50×10 3 or more and 1.50×10 4 or less. When the number average molecular weight is 3.00×10 4 or less, the solubility of the unsaturated polyester resin in the solvent tends to be even better. Therefore, an embodiment in which the number average molecular weight is 3.00×10 4 or less can be suitably used, for example, in applications such as impregnating fillers (e.g., glass cloth) such as copper-clad laminates, or in applications where it is dissolved in a solvent and used like an unsaturated polyester. Also, when the number average molecular weight of the unsaturated polyester resin is 3.00×10 4 or less, it tends to be more reliably possible to prevent bleed-out (a phenomenon in which the resin does not react uniformly and the same composition accumulates at a visually observable level) when cured by mixing with other unsaturated polyester resins such as maleimide resins. On the other hand, when the number average molecular weight of the unsaturated polyester resin of the present embodiment is 5.00×102 In the above case, there is a tendency to sufficiently incorporate dihydroxy units into the resin, and there is a tendency for the dielectric properties to be further improved. The number average molecular weight can be measured by gel permeation chromatography (GPC). The number average molecular weight in the GPC measurement shall be determined under the conditions described in the examples below.

[0047] The unsaturated polyester resin of the present embodiment includes all aspects of unsaturated polyester resins obtained by arbitrarily combining all of the above-described aspects.

[0048] [Method for Producing Unsaturated Polyester Resin] One embodiment of the present invention relates to a method for producing an unsaturated polyester resin. The above-described unsaturated polyester resin can be produced by applying various known synthetic routes and synthetic methods, and the production method is not particularly limited. Hereinafter, a preferred production method will be described in detail.

[0049] The method for producing an unsaturated polyester resin of the present embodiment includes at least one of a compound represented by the following formula (4) (hereinafter, also referred to as a "dicarboxylic acid compound") and / or a compound represented by the following formula (4') (hereinafter, also referred to as a "dicarboxylic anhydride") and [Chemical formula] [Chemical formula] a compound represented by the following formula (5) (hereinafter, also referred to as a "dihydroxy compound") and [Chemical formula] reacting them. Here, in the above formula (4), R 1 is a divalent linking group having one or more ethylenically unsaturated bonds, and R 3 and R 4 are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. In the above formula (4'), R 1is R in the above formula (4) 1 and has the same meaning. In the above formula (5), R 2 and R 3 are each independently a linear or branched hydrocarbon linking group having 1 to 10 carbon atoms, and R 5 and R 6 are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, and n is the number of repeating units.

[0050] In the method for producing an unsaturated polyester resin of the present embodiment, when the dicarboxylic acid compound and / or dicarboxylic anhydride undergoes an esterification reaction and is incorporated into the resin, the dicarboxylic acid unit of the unsaturated polyester resin of the present embodiment is generated. Similarly, when the dihydroxy compound undergoes an esterification reaction and is incorporated into the resin, the dihydroxy unit of the unsaturated polyester resin of the present embodiment is generated. That is, the dicarboxylic acid unit and dihydroxy unit of the unsaturated polyester resin of the present embodiment are structural units derived from the above-mentioned dicarboxylic acid compound and / or dicarboxylic anhydride and dihydroxy compound, respectively.

[0051] R in the above formulas (4) and (4') 1 has the same meaning as R in the above formula (1) 1 , and the preferred embodiments are also as described above. Also, R in the above formula (5) 2 and R 3 have the same meaning as R and R in the above formula (2) 2 and 3 respectively, and the preferred embodiments are also as described above.

[0052] R in the above formula (4) 3 and R 4 , and R in the above formula (5) 5 and R 6 are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. When the dicarboxylic acid compound and / or dicarboxylic anhydride reacts with the dihydroxy compound and is incorporated into the resin, dehydration condensation occurs by the esterification reaction and the reaction proceeds.

[0053] The R in the above formula (4) 3 and R 4 , and the R in the above formula (5) 5 and R 6 are each independently preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a phenyl group, or a benzyl group, more preferably a hydrogen atom, a methyl group, an ethyl group, or a phenyl group, still more preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom.

[0054] In the above formula (5), n is the number of repeating units and is not particularly limited, but is preferably 5 or more and 33 or less, more preferably 10 or more and 32 or less, still more preferably 15 or more and 31 or less, particularly preferably 20 or more and 30 or less, and most preferably 23 or more and 29 or less. When n in the above formula (5) is within the above preferred numerical range, good compatibility, appropriate viscosity, and hydroxyl value can be maintained, and as a result, the handleability, productivity, economy, etc. during synthesis tend to improve. Note that the number of repeating units n can be easily known from catalog values or the like when the raw material can be specified, and the value described in such catalog values or the like is adopted as the number of repeating units n. Otherwise, for example, when the structure and molecular weight of the raw material are known, the number of repeating units n can be determined as an average value by calculation based on these. Here, when the structure and molecular weight of the raw material are unknown, the structure and molecular weight of the raw material can be specified by known measurement methods such as NMR and GPC.

[0055] The number average molecular weight of the dihydroxy compound represented by the above formula (5) is not particularly limited, but is preferably 5.00×10 2 or more and 1.80×10 3 or less, more preferably 9.00×10 2 or more and 1.70×10 3 or less, still more preferably 1.20×10 3 or more and 1.65×10 3 or less, particularly preferably 1.40×10 3 or more and 1.60×10 3The following is the case. When the number average molecular weight is 5.00×10 2 or more and 1.80×10 3 or less, good compatibility, appropriate viscosity, and hydroxyl value can be maintained. As a result, the handleability, productivity, economy, etc. during synthesis tend to improve. In addition, when the raw material can be specified, the number average molecular weight can be easily known from catalog values, etc. In this case, the value described in the catalog values, etc. is adopted as the number average molecular weight. Also, when the catalog values, etc. are unknown, the number average molecular weight can be measured by gel permeation chromatography (GPC). The number average molecular weight in the GPC measurement of the dihydroxy compound represented by the above formula (5) is not particularly limited, but preferably 1.60×10 2 or more and 4.10×10 3 or less, more preferably 1.80×10 2 or more and 4.00×10 3 or less, still more preferably 2.00×10 3 or more and 3.80×10 3 or less, and particularly preferably 2.20×10 3 or more and 3.50×10 3 or less. When the number average molecular weight in the GPC measurement is 1.60×10 2 or more and 4.10×10 3 or less, good compatibility, appropriate viscosity, and hydroxyl value can be maintained. As a result, the handleability, productivity, economy, etc. during synthesis tend to improve. Note that the number average molecular weight in the GPC measurement shall be carried out under the conditions described in the examples below.

[0056] In a preferred embodiment of the method for producing an unsaturated polyester resin of the present embodiment, a dicarboxylic anhydride is used, and a dihydroxy compound in which R 5 and R 6 in the above formula (5) are hydrogen atoms is used. Further, in another preferred embodiment of the method for producing an unsaturated polyester resin of the present embodiment, a dicarboxylic acid compound in which R 3 and R 4 in the above formula (4) are hydrogen atoms, and / or R 5 and R 6A dihydroxy compound in which the is a hydrogen atom is used. According to these preferred embodiments, there is a tendency to be able to efficiently produce an unsaturated polyester resin.

[0057] The above dicarboxylic acid compound, dicarboxylic anhydride, and dihydroxy compound may be used alone or in combination of two or more.

[0058] In the method for producing an unsaturated polyester resin of the present embodiment, monomers, oligomers, polymers, etc. other than the dicarboxylic acid compound represented by the above formula (4), the dicarboxylic anhydride represented by the above formula (4'), and the dihydroxy compound represented by the above formula (5) may be added to the reaction system and incorporated into the unsaturated polyester resin. Such compounds include dicarboxylic acid compounds other than the dicarboxylic acid compound represented by the above formula (4), dicarboxylic anhydrides other than the dicarboxylic anhydride represented by the above formula (4'), dihydroxy compounds other than the dihydroxy compound represented by the above formula (5), monohydroxy compounds having an ethylenically unsaturated double bond, silicone oils having a hydroxy group in the molecular structure, silicone oils having a carboxy group in the molecular structure, and the like. Examples of these compounds include those described in detail in the description of the unsaturated polyester resin of the present embodiment. These compounds may be used alone or in combination of two or more.

[0059] The usage amounts of the dicarboxylic acid compound represented by the above formula (4), the dicarboxylic anhydride represented by the above formula (4'), and the dihydroxy compound represented by the above formula (5) are the molar ratio N in the unsaturated polyester resin of the present embodiment COOH / N OH It is preferably adjusted so as to be within the above preferred range. That is, the total amount of the dicarboxylic acid compound represented by the above formula (4) and the dicarboxylic anhydride represented by the above formula (4') with respect to the amount of the dihydroxy compound represented by the formula (5) is not particularly limited, but in terms of molar ratio, it is preferably 0.50 or more and 5.0 or less, more preferably 0.60 or more and 3.0 or less, still more preferably 0.70 or more and 2.0 or less, and particularly preferably 0.75 or more and 1.50 or less. Regarding the amounts of the respective compounds used, the amount of the more volatile compound may be increased using the ease of evaporation of each compound (for example, the saturated vapor pressure at the reaction temperature) as an index.

[0060] The ratio of the sum of the amounts of the dicarboxylic acid compound represented by the above formula (4), the dicarboxylic anhydride represented by the above formula (4'), and the dihydroxy compound represented by the above formula (5) to the total amount of the compounds used in the method for producing the unsaturated polyester resin of the present embodiment is not particularly limited, but in terms of molar ratio, it is preferably 0.60 or more, more preferably 0.70 or more, still more preferably 0.80 or more, and particularly preferably 0.90 or more. The upper limit value of the above ratio is not particularly limited, but it may be, for example, 1.0, 0.98, or 0.96. By setting the above ratio to 0.60 or more, there is a tendency to be able to produce an unsaturated polyester resin that is more excellent in dielectric properties, solvent solubility, bleed-out resistance, etc.

[0061] From the viewpoint of obtaining an unsaturated polyester resin that is more excellent in dielectric properties, solvent solubility, bleed-out resistance, etc., among all the compounds having two carboxy groups and their anhydrides used in the production method of the present embodiment, the ratio of the sum of the amounts of the dicarboxylic acid compound and the dicarboxylic anhydride represented by the above formula (4) or the above formula (4') is preferably 0.60 or more, more preferably 0.70 or more, still more preferably 0.80 or more, and even more preferably 0.90 or more in terms of molar ratio. The upper limit value of the ratio is not particularly limited, but it may be, for example, 1.0, 0.98, or 0.96. From the same perspective, among all the compounds having two hydroxy groups used in the production method of the present embodiment, the proportion of the amount of the dihydroxy compound represented by the above formula (5) is preferably 0.60 or more, more preferably 0.70 or more, still more preferably 0.80 or more, and even more preferably 0.90 or more. The upper limit of the proportion is not particularly limited, and may be, for example, 1.0, 0.98, or 0.96.

[0062] In one aspect, the method for producing an unsaturated polyester resin of the present embodiment may include a step A of reacting at least one of the dicarboxylic acid compound represented by the above formula (4) and the dicarboxylic anhydride represented by the above formula (4’) with the dihydroxy compound represented by the above formula (5).

[0063] The reaction in step A may be carried out by heating the reactants at normal pressure. The reaction in step A may also be carried out by heating the reactants at normal pressure and then further heating under reduced pressure. The reaction temperature in step A is not particularly limited as long as it is a temperature-rising condition. For example, it is 80 to 290 °C (including both end values. The same applies throughout this specification unless otherwise specified), preferably 120 to 270 °C, and more preferably 150 to 250 °C. When the reaction is carried out under reduced pressure in step A, the pressure in the system is not particularly limited as long as it is a reduced pressure condition. For example, it is 100 kPa or less, preferably 50 kPa or less, more preferably 30 kPa or less, and still more preferably 15 kPa or less.

[0064] Step A is preferably carried out in the presence of an inert gas. Examples of the inert gas include nitrogen gas and argon gas.

[0065] In Process A, each reactant, if it is a solid, may be supplied as a solid, or may be heated to a molten state for supply, or may be supplied as an aqueous solution; if it is a liquid, it may be supplied as a single liquid or as a mixture with a solvent. Also, the reaction format may be any of batch, continuous, or a combination of batch and continuous methods.

[0066] Process A is preferably carried out in the presence of a catalyst. Examples of the catalyst include those generally used in the synthesis of polyesters. Specifically, examples include salts of alkali metal compounds, alkaline earth metal compounds, nitrogen-containing compounds, and titanium, tin, zinc, zirconium, and / or lead. It is also possible to use basic compounds such as basic boron compounds and basic phosphorus compounds in combination with alkali metal compounds and / or alkaline earth metal compounds as auxiliary agents.

[0067] Examples of the alkali metal compound include organic acid salts, inorganic salts, oxides, hydroxides, hydrides, alkoxides, etc. of alkali metals. Specifically, sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, sodium hydrogen carbonate, potassium hydrogen carbonate, lithium hydrogen carbonate, cesium hydrogen carbonate, sodium carbonate, potassium carbonate, lithium carbonate, cesium carbonate, sodium acetate, potassium acetate, lithium acetate, cesium acetate, sodium stearate, potassium stearate, lithium stearate, cesium stearate, sodium borohydride, potassium borohydride, lithium borohydride, cesium borohydride, sodium phenylborate, potassium phenylborate, lithium phenylborate, cesium phenylborate, sodium benzoate, potassium benzoate, lithium benzoate, cesium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, dicesium hydrogen phosphate, disodium phenylphosphate, dipotassium phenylphosphate, dilithium phenylphosphate, dicesium phenylphosphate, alcoholates, phenolates of sodium, potassium, lithium, cesium, disodium salt, dipotassium salt, dilithium salt, dicesium salt of bisphenol A, etc. may be mentioned.

[0068] Examples of the alkaline earth metal compound include organic acid salts, inorganic salts, oxides, hydroxides, hydrides, alkoxides, etc. of alkaline earth metal compounds. Specifically, calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium hydrogen carbonate, barium hydrogen carbonate, magnesium hydrogen carbonate, strontium hydrogen carbonate, calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, strontium stearate, etc. may be mentioned.

[0069] Examples of the nitrogen-containing compounds include quaternary ammonium hydroxides and their salts, amines, etc. Specifically, quaternary ammonium hydroxides having an alkyl group and / or an aryl group such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylbenzylammonium hydroxide; tertiary amines such as triethylamine, dimethylbenzylamine, triphenylamine; secondary amines such as diethylamine, dibutylamine; primary amines such as propylamine, butylamine; imidazoles such as 2-methylimidazole, 2-phenylimidazole, benzimidazole; or bases or basic salts such as ammonia, tetramethylammonium borohydride, tetrabutylammonium borohydride, tetrabutylammonium tetraphenylborate, tetraphenylammonium tetraphenylborate, etc.

[0070] Examples of the titanium salts include tetramethyl titanate, tetrabutyl titanate, tetrapropyl titanate, tetraisopropyl titanate, tetraisobutyl titanate, and tetraphenyl titanate. Examples of the tin salts include tin(II) chloride, tin(IV) chloride, tin(II) acetate, tin(IV) acetate, dibutyltin oxide, dibutyltin dilaurate, dibutyltin dimethoxide, and dibutyltin diacetate. Examples of the zinc salts include zinc acetate, zinc benzoate, and zinc 2-ethylhexanoate. Examples of the zirconium salts include zirconium acetylacetonate, zirconium oxyacetate, and zirconium tetrabutoxide. Examples of the lead salts include lead(II) acetate and lead(IV) acetate.

[0071] Examples of basic boron compounds that can be used in combination with alkali metal compounds and / or alkaline earth metal compounds include sodium salts, potassium salts, lithium salts, calcium salts, barium salts, magnesium salts, and strontium salts such as tetramethylboron, tetraethylboron, tetrapropylboron, tetrabutylboron, trimethylethylboron, trimethylbenzylboron, trimethylphenylboron, triethylmethylboron, triethylbenzylboron, triethylphenylboron, tributylbenzylboron, tributylphenylboron, tetraphenylboron, benzyltriphenylboron, methyltriphenylboron, and butyltriphenylboron.

[0072] Examples of basic phosphorus compounds include triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, tributylphosphine, and quaternary phosphonium salts.

[0073] In addition, as catalysts commonly used in the synthesis of polyesters, antimony compounds such as antimony trioxide; germanium compounds such as germanium dioxide and germanium tetroxide; manganese compounds, etc., and catalysts disclosed in U.S. Patent Nos. 4,025,492, 4,136,089, 4,176,224, 4,238,593, and 4,208,527, and R.E. Wilfong, Journal of Polymer Science, 54, 385, (1961), etc. are also included.

[0074] The above catalysts may be used alone or in combination of two or more. In the production method of this embodiment, a titanium salt catalyst is preferably used. In the mode of using a catalyst, the catalyst may be added in Step A, and in Step A, it may be added all at once, intermittently, or discontinuously.

[0075] The amount of the catalyst used is not particularly limited. For example, it is 0.1 to 500 μmol, preferably 0.50 to 100 μmol in terms of metal atoms, per 1 mol of the total dihydroxy compound used in the reaction.

[0076] In the above step A, compounds other than the dicarboxylic acid compound represented by the above formula (4), the dicarboxylic anhydride represented by the above formula (4'), and the dihydroxy compound represented by the above formula (5) may be added to the reaction system and reacted. The method for producing an unsaturated polyester resin of the present embodiment may have another step other than the above step A in order to react only the above-described compounds other than the dicarboxylic acid compound represented by the above formula (4), the dicarboxylic anhydride represented by the above formula (4'), and the dihydroxy compound represented by the above formula (5).

[0077] The method for producing an unsaturated polyester resin of the present embodiment may include a step of purifying the obtained product after reacting a dicarboxylic acid compound and / or a dicarboxylic anhydride with a dihydroxy compound as described above. The purification step may be a step of removing unreacted reactants and / or by-products and / or catalyst components incorporated into the unsaturated polyester resin. Examples of by-products include compounds produced by the condensation reaction of a dicarboxylic anhydride and a dihydroxy compound. As the purification step, a method generally used as a resin purification method may be appropriately used. Specifically, there are mentioned a reprecipitation method in which an unsaturated polyester resin is dissolved in a solvent and then dropped into a poor solvent or water, and a liquid-liquid extraction method. As the purification step, liquid-liquid extraction using toluene and an aqueous sodium carbonate solution is preferably used. Since such a method uses toluene having a low dielectric constant as the oil phase, there is a tendency to obtain an unsaturated polyester resin having more excellent dielectric properties after purification.

[0078] In the method for producing an unsaturated polyester resin of the present embodiment, "Polyester Resin Handbook" (written by Eijiro Takiyama, published by Nikkan Kogyo Shimbun) may be appropriately referred to.

[0079] The method for producing an unsaturated polyester resin according to this embodiment includes all aspects of the methods for producing unsaturated polyester resins obtained by arbitrarily combining all the above-described aspects.

[0080] [Resin Composition] One embodiment of the present invention relates to a resin composition containing the unsaturated polyester resin according to this embodiment. The resin composition according to this embodiment may further contain another component in addition to the unsaturated polyester resin according to this embodiment, if necessary.

[0081] The resin composition according to this embodiment can be a composition that cures in response to an appropriate stimulus or spontaneously. In one aspect, the resin composition according to this embodiment is a thermosetting resin composition, and in another aspect, it is a photocurable resin composition. As yet another aspect, the resin composition according to this embodiment is a thermally and / or photocurable resin composition.

[0082] Examples of other components that the resin composition according to this embodiment may contain include, but are not particularly limited to, epoxy resins, cyanate ester compounds, maleimide compounds, BT resins, compounds having polymerizable unsaturated groups, compounds having an ester structure derived from a phenol group and an aromatic carboxylic acid group, modified silicone oils, heat stabilizers, antioxidants, curing agents, and curing accelerators. The above-mentioned other components that may be contained may be used alone or in combination of two or more.

[0083] Examples of the epoxy resin include phenolic phenyl aralkyl novolak type epoxy resin, phenolic biphenyl aralkyl type epoxy resin, naphthol aralkyl type epoxy resin, anthraquinone type epoxy resin, polyoxynaphthalene type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, trifunctional phenol type epoxy resin, tetrafunctional phenol type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, aralkyl novolak type epoxy resin, alicyclic epoxy resin, polyol type epoxy resin, compounds obtained by epoxidizing double bonds such as glycidylamine, glycidyl ester, or butadiene, compounds obtained by reacting hydroxyl group-containing silicone resins with epichlorohydrin, and their halides and the like. These may be used alone or in combination of two or more.

[0084] Examples of the cyanate ester compound include naphthol aralkyl type cyanate ester compounds, novolak type cyanate esters, phenol biphenyl aralkyl type cyanate ester compounds, bis(3,5-dimethyl-4-cyanatophenyl)methane, bis(4-cyanatophenyl)methane, 1,3-dicyanatobenzene, 1,4-dicyanatobenzene, 1,3,5-tricyanatobenzene, 1,3-dicyanatronaphthalene, 1,4-dicyanatronaphthalene, 1,6-dicyanatronaphthalene, 1,8-dicyanatronaphthalene, 2,6-dicyanatronaphthalene, 2,7-dicyanatronaphthalene, 1,3,6-tricyanatronaphthalene, 4,4'-dicyanatobiphenyl, bis(4-cyanatophenyl)ether, bis(4-cyanatophenyl)thioether, bis(4-cyanatophenyl)sulfone, 2,2-bis(4-cyanatophenyl)propane, polymethylene polyphenyl polyisocyanate, m-tetramethylxylylene diisocyanate, hydrogenated xylylene diisocyanate (1,3-bis(isocyanatomethyl)cyclohexane), isophorone diisocyanate, norbornene diisocyanate, dicyclohexylmethane diisocyanate, hydrogenated methylene bisphenylene diisocyanate, 1,4-cyclohexane diisocyanate 1,6-hexamethylene diisocyanate, trimethylene diisocyanate, trifunctional isocyanates having an isocyanurate ring formed by trimerization of bifunctional isocyanate compounds, and the like. These may be used alone or in combination of two or more.

[0085] Examples of the maleimide compound include N-phenylmaleimide, N-hydroxyphenylmaleimide, bis(4-maleimidophenyl)methane, 2,2-bis{4-(4-maleimidophenoxy)-phenyl}propane, bis(3,5-dimethyl-4-maleimidophenyl)methane, bis(3-ethyl-5-methyl-4-maleimidophenyl)methane, bis(3,5-diethyl-4-maleimidophenyl)methane, prepolymers of these maleimide compounds, prepolymers of maleimide compounds and amine compounds, and the like. These may be used alone or in combination of two or more.

[0086] The BT resin is obtained by dissolving a cyanate ester compound and a maleimide compound in a solvent-free or organic solvent such as methyl ethyl ketone, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, toluene, xylene, etc., heating and mixing them, and prepolymerizing them. Here, the above-mentioned cyanate ester compound and maleimide compound can be used. These may be used alone or in combination of two or more.

[0087] The compound having a polymerizable unsaturated group is not particularly limited. For example, vinyl compounds such as ethylene, styrene, divinylbenzene, divinylbiphenyl; (meth)acrylates of monohydric or polyhydric alcohols such as methyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, tricyclodecanol (meth)acrylate, tricyclodecanol di(meth)acrylate, tricyclodecanol tri(meth)acrylate, polypropylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate; epoxy (meth)acrylates such as bisphenol A type epoxy (meth)acrylate, bisphenol F type epoxy (meth)acrylate; allyl compounds such as allyl chloride, allyl acetate, allyl ether, propylene, triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, diallyl isophthalate, diallyl maleate; benzocyclobutene resin; (bis)maleimide resin, etc. These compounds having a polymerizable unsaturated group can be used alone or in a mixture of two or more.

[0088] Examples of the compound having an ester structure derived from a phenol group and an aromatic carboxylic acid group include an active ester resin (I) using, as a reaction raw material, a compound selected from a compound (a1) having one phenolic hydroxyl group, a compound (a2) having two or more phenolic hydroxyl groups, and an aromatic polycarboxylic acid or its acid halide (a3); and an active ester resin (II) using, as a reaction raw material, a compound selected from a compound (b1) having two or more phenolic hydroxyl groups, an aromatic monocarboxylic acid or its acid halide (b2), and an aromatic polycarboxylic acid or its acid halide (b3). Specific examples of these compounds can be referred to in International Publication No. 2020 / 003824. These may be used alone or in combination of two or more.

[0089] Examples of the modified silicone oil include those having a chain siloxane skeleton and having a group other than a hydrogen or hydrocarbon group in the molecular structure. Examples of the modifying group include an epoxy group, an amino group, a hydroxyl group, a methacryl group, a mercapto group, a carboxy group, an alkoxy group, and a silanol group. These may be used alone or in combination of two or more.

[0090] Examples of heat stabilizers include phosphorous acid, phosphoric acid, phosphonic acid, phosphinic acid, and their esters. Specifically, examples include triphenyl phosphite, tris(nonylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, trioctadecyl phosphite, didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl monophenyl phosphite, monobutyl diphenyl phosphite, monodecyl diphenyl phosphite, monooctyl diphenyl phosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl) octyl phosphite, bis(nonylphenyl)pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, distearylpentaerythritol diphosphite, tributyl phosphate, triethyl phosphate, trimethyl phosphate, triphenyl phosphate, diphenyl monoorthoxenyl phosphate, dibutyl phosphate, dioctyl phosphate, diisopropyl phosphate, tetrakis(2,4-di-tert-butylphenyl) 4,4'-biphenylenediphosphonate, dimethyl benzenephosphonate, diethyl benzenephosphonate, dipropyl benzenephosphonate, etc. These may be used alone or in combination of two or more.

[0091] Examples of the antioxidant include pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(3-laurylthiopropionate), glycerol-3-stearylthiopropionate, triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, N,N-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 3,5-di-tert-butyl-4-hydroxy-benzylphosphonate-diethyl ester, tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, tetrakis(2,4-di-tert-butylphenyl) 4,4'-biphenylenediphosphonate, 3,9-bis{1,1-dimethyl-2-[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl}-2,4,8,10-tetraoxaspiro(5,5)undecane, and the like. These may be used alone or in combination of two or more.

[0092] Examples of the curing agent include polyfunctional phenol compounds such as phenol novolak, cresol novolak, and aminotriazine novolak resin; amine compounds such as dicyandiamide, diaminodiphenylmethane, and diaminodiphenylsulfone; and acid anhydrides such as phthalic anhydride, pyromellitic anhydride, and maleic anhydride. Examples of the curing accelerator include organometallic salts and organometallic complexes such as zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, cobalt(II) bisacetylacetonate, cobalt(III) trisacetylacetonate, zinc(II) acetylacetonate, and iron(III) acetylacetonate; imidazoles and their derivatives; organophosphorus compounds; secondary amines; tertiary amines; and quaternary ammonium salts. These may be used alone or in combination of two or more.

[0093] Among the above components, the resin composition of the present embodiment preferably contains a component that reacts with the unsaturated polyester resin of the present embodiment and cures together. Examples of such components include (meth)acrylates, isocyanurates, epoxy resins, maleimide compounds, cyanate ester compounds, BT resins, compounds having a vinyl group, and compounds having an allyl group.

[0094] The resin composition of the present embodiment may further contain an initiator for initiating curing, if necessary. As the initiator, known initiators such as thermal initiators and photoinitiators can be used, and the type thereof is not particularly limited. Preferred initiators include organic peroxide-based initiators that initiate curing by heating and ultraviolet initiators that initiate curing by light irradiation, but are not particularly limited thereto.

[0095] Examples of the organic peroxide-based initiator include ketone peroxides such as methyl ethyl ketone peroxide and acetylacetone peroxide; diacyl peroxides such as benzoyl peroxide; peroxy esters such as t-butyl peroxybenzoate; hydroperoxides such as cumene hydroperoxide; and dialkyl peroxides such as dicumyl peroxide.

[0096] Examples of the ultraviolet initiator include benzophenones such as benzophenone, benzyl, and methyl orthobenzoyl benzoate; benzoin ethers such as benzoin alkyl ether; acetophenones such as benzyldimethyl ketal, 2,2 - diethoxyacetophenone, 2 - hydroxy - 2 - methylpropiophenone, 4 - isopropyl - 2 - hydroxy - 2 - methylpropiophenone, and 1,1 - dichloroacetophenone; and thioxanthones such as 2 - chlorothioxanthone, 2 - methylthioxanthone, and 2 - isopropylthioxanthone.

[0097] The resin composition of this embodiment may further contain a cross - linking agent, if necessary. However, since the unsaturated polyester resin of this embodiment has an ethylenically unsaturated bond, it can be cured alone without using a cross - linking agent. Therefore, the resin composition of this embodiment may not contain a cross - linking agent.

[0098] The content of the unsaturated polyester resin of this embodiment contained in the resin composition of this embodiment can be appropriately set according to the desired performance and is not particularly limited. The content of the unsaturated polyester resin of this embodiment may be, for example, 0.50 parts by mass or more with respect to 100 parts by mass of the resin component (the resin and the components that cure together with the resin. Synonymous with the solid component). For example, when the unsaturated polyester resin of this embodiment is added to the resin composition as a compatibilizer, the content of the unsaturated polyester resin of this embodiment may be, for example, 0.50 parts by mass or more and 10 parts by mass or less, or 3.0 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the resin component.

[0099] Alternatively, the content of the unsaturated polyester resin of the present embodiment contained in the resin composition of the present embodiment may be, for example, 10 parts by mass or more, 20 parts by mass or more, 30 parts by mass or more, 50 parts by mass or more, 70 parts by mass or more, 80 parts by mass or more, 90 parts by mass or more, or 95 parts by mass or more with respect to 100 parts by mass of the resin component. When the content of the unsaturated polyester resin of the present embodiment is within the above range, there is a tendency to obtain a resin composition having excellent dielectric properties. In addition, the cured product of such a resin composition tends to have a low yellowness, that is, a good color tone. The upper limit of the content of the unsaturated polyester resin of the present embodiment contained in the resin composition of the present embodiment is not particularly limited and may be 100 parts by mass or less, 99 parts by mass or less, 95 parts by mass or less, 90 parts by mass or less, 80 parts by mass or less, or 75 parts by mass or less with respect to 100 parts by mass of the resin component. In addition, the content of components other than the unsaturated polyester resin of the present embodiment contained in the resin composition of the present embodiment may be appropriately adjusted within the range in which the content of the unsaturated polyester resin of the present embodiment in the resin composition is within the above range. For example, the content of resin components other than the unsaturated polyester resin of the present embodiment contained in the resin composition of the present embodiment is not particularly limited and may be 1 part by mass or more, 3 parts by mass or more, 5 parts by mass or more, 10 parts by mass or more, 15 parts by mass or more, 20 parts by mass or more, or 25 parts by mass or more with respect to 100 parts by mass of the resin composition. The upper limit thereof is not particularly limited, but may be, for example, 90 parts by mass or less, 80 parts by mass or less, or 70 parts by mass or less.

[0100] The resin composition of the present embodiment may further contain fillers such as a reinforcing base material and an inorganic filler, if necessary. The inorganic filler is not particularly limited as long as it is commonly used in the industry. Specifically, for example, silicas such as natural silica, fused silica, amorphous silica, and hollow silica; metal hydroxides such as aluminum hydroxide, heat-treated aluminum hydroxide (aluminum hydroxide heat-treated to reduce a part of the crystal water), magnesium hydroxide, and boehmite; nitride compounds such as aluminum nitride and boron nitride; molybdenum compounds such as molybdenum oxide and zinc molybdate; zinc borate, zinc stannate, alumina, clay, kaolin, talc, fired clay, fired kaolin, fired talc, mica, glass short fibers (glass fine powders such as E glass and D glass), hollow glass, spherical glass, titanium oxide, silicone rubber, silicone composite powder, etc. can be mentioned. Examples of the reinforcing base material include paper, glass cloth, glass non-woven fabric, aramid paper, aramid cloth, glass mat, glass roving cloth, etc. The filler and the reinforcing base material may be used alone or in combination of two or more.

[0101] The content of the filler contained in the resin composition of this embodiment can be appropriately set according to the desired performance and is not particularly limited, but it may be, for example, 1 to 2000 parts by mass with respect to 100 parts by mass of the resin component. The content of the filler can be appropriately changed depending on the use of the resin composition.

[0102] The resin composition of this embodiment may further contain a silane coupling agent or a wetting dispersant in addition to the filler, if necessary. By containing these components, the dispersibility of the filler, particularly the inorganic filler, is improved, and furthermore, the adhesion strength between the resin and the filler tends to be improved. As the silane coupling agent, there is no particular limitation as long as it is a silane coupling agent generally used for the surface treatment of inorganic substances. Specifically, for example, amino-silane-based silane coupling agents such as γ-aminopropyltriethoxysilane and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane; epoxy-silane-based silane coupling agents such as γ-glycidoxypropyltrimethoxysilane; vinyl-silane-based silane coupling agents such as γ-methacryloxypropyltrimethoxysilane; cationic-silane-based silane coupling agents such as N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride; phenyl-silane-based silane coupling agents; styryl-silane-based coupling agents such as p-styryltrimethoxysilane, p-styryltriethoxysilane, p-styrylmethyldimethoxysilane, p-styrylmethyldiethoxysilane, and N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, etc. can be mentioned. As the wetting dispersant, there is no particular limitation as long as it is a dispersion stabilizer used for paints. Specifically, for example, wetting dispersants such as Disperbyk-110, 111, 180, 161, BYK-W996, W9010, and W903 manufactured by Big Chemie Japan Co., Ltd. can be mentioned. These silane coupling agents and wetting dispersants may be used alone or in combination of two or more.

[0103] Furthermore, the resin composition of this embodiment may contain a solvent if necessary. When the resin composition contains an organic solvent, the viscosity during the preparation of the resin composition tends to decrease, and the handleability tends to improve. The solvent is not particularly limited as long as it can dissolve at least one component in the resin composition. Specifically, for example, ketones such as acetone, methyl ethyl ketone, and methyl cellosolve; aromatic hydrocarbons such as toluene and xylene; amides such as dimethylformamide; propylene glycol methyl ether and its acetate, etc. can be mentioned. The solvent may be used alone or in combination of two or more.

[0104] [Cured product] One embodiment of the present invention relates to a cured product of the unsaturated polyester resin of this embodiment and a cured product of the resin composition of this embodiment. Since the cured product of this embodiment is a cured product containing the unsaturated polyester resin of this embodiment, it has excellent dielectric properties. In addition, the cured product of this embodiment tends to have a good color tone.

[0105] As a method for curing the unsaturated polyester resin or the resin composition of this embodiment, known methods can be applied, and it is not particularly limited. It may be appropriately selected according to the type and composition of the resin, the type and composition of the resin composition, the required performance, etc. Examples of the curing method include thermal curing and photo-curing. When curing the resin composition, it is preferable to dissolve and mix the unsaturated polyester resin or the resin composition in a solvent once so that each component is uniformly mixed, and then cure the dried product.

[0106] [Applications] The applications of the unsaturated polyester resin, resin composition, and their cured products of this embodiment are not particularly limited, and examples include electronic material applications. Specifically, for example, electronic components, semiconductor encapsulation materials, mold resins, rigid substrates, prepregs, laminates, copper foils with resin, circuit boards, underfill materials, and build-up films can be mentioned. In addition, it can be used as a fiber-reinforced composite material such as carbon fiber-reinforced plastic and glass fiber-reinforced plastic together with additives such as epoxy resins or alone.

[0107] A preferred aspect of the fiber-reinforced composite material includes the resin composition of this embodiment and reinforcing fibers. By curing the fiber-reinforced composite material of this embodiment, a fiber-reinforced molded product can be manufactured. The reinforcing fibers are not particularly limited, and examples include glass fibers, carbon fibers, boron fibers, and aramid fibers. A preferred aspect of the semiconductor encapsulation material includes the resin composition of this embodiment and an inorganic filler. The semiconductor encapsulation material of this embodiment is used in the manufacture of semiconductor devices. As the inorganic filler, those described above can be used.

[0108] A preferred embodiment of the prepreg includes a base material and the resin composition of the present embodiment impregnated or coated on the base material. The prepreg of the present embodiment can be manufactured according to a conventional method, and the manufacturing method is not particularly limited. For example, after impregnating or coating the resin composition on the base material, it can be produced by heating in a dryer at 100 to 200 °C for 1 to 30 minutes to semi-cure (B-stage). The base material is not particularly limited, and known ones used in various printed wiring board materials can be appropriately selected and used according to the intended use and performance. Specific examples of the fibers constituting the base material are not particularly limited. For example, glass fibers such as E-glass, D-glass, S-glass, Q-glass, spherical glass, NE-glass, L-glass, T-glass; inorganic fibers other than glass such as quartz; polyparaphenylene terephthalamide (Kevlar (registered trademark), manufactured by DuPont Co., Ltd.), copolyparaphenylene·3,4'-oxydiphenylene·terephthalamide (Technora (registered trademark), manufactured by Teijin Technoproducts Co., Ltd.) and other wholly aromatic polyamides; polyesters such as 2,6-hydroxy naphthoic acid·para-hydroxybenzoic acid (Vectran (registered trademark), manufactured by Kuraray Co., Ltd.), Zexion (registered trademark, manufactured by KB Seiren Co., Ltd.); organic fibers such as polyparaphenylene benzoxazole (Zylon (registered trademark), manufactured by Toyobo Co., Ltd.), polyimide. These base materials may be used alone or in combination of two or more.

[0109] A preferred embodiment of the laminate is a laminate including at least the prepreg of the present embodiment described above. The laminate of the present embodiment can be obtained, for example, by laminating and molding in combination the prepreg of the present embodiment described above and other layers. The other layers are not particularly limited, and examples include separately manufactured wiring boards for inner layers.

[0110] A preferred embodiment of the circuit board includes the laminate of the present embodiment described above and metal foil disposed on one or both sides of the laminate. Another preferred embodiment of the circuit board is, for example, a copper foil-clad laminate obtained by laminating and curing the prepreg of the present embodiment described above and copper foil. The copper foil to be used is not particularly limited as long as it is used for a circuit board, but known copper foils such as rolled copper foil and electrolytic copper foil are preferred.

[0111] A preferred embodiment of the build-up film includes a cured product of the resin composition of the present embodiment described above and a base film. "Build-up" means producing a multilayer printed wiring board by laminating a prepreg or a resin sheet and repeating hole drilling, wiring formation, etc. for each layer.

[0112] As further effects in various embodiments of the present embodiment, for example, low dielectric characteristics, bleed-out resistance, low thermal expansion, crack prevention, good color tone, solvent solubility, and suppression of separation between resins during curing are assumed.

Examples

[0113] Hereinafter, the features of the present invention will be described more specifically by way of preparation examples, examples, comparative examples, etc., but the present invention is not limited thereto. That is, the materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples, etc. can be appropriately changed without departing from the spirit of the present invention. Also, the values of various manufacturing conditions and evaluation results in the following examples, etc. have the meaning as preferred upper limit values or preferred lower limit values in the embodiments of the present invention, and the preferred numerical range may be a range defined by a combination of the above upper limit value or lower limit value and the values of the following examples or the values between the examples.

[0114] [Measurement of the number average molecular weight of unsaturated polyester and dihydroxy compound] An unsaturated polyester resin or a dihydroxy compound was dissolved in tetrahydrofuran so that the resin concentration became 0.2 mass%, and it was measured by gel permeation chromatography (GPC). The number average molecular weight of each unsaturated polyester resin was calculated using a calibration curve prepared with standard polystyrene. GPC was measured at a column temperature of 40 °C using a column TSKgel SuperHM-M manufactured by Tosoh Corporation. The eluent was flowed at a flow rate of 0.6 ml / min of tetrahydrofuran and measured with a refractive index detector.

[0115] [Production of Unsaturated Polyester Resin] [Preparation Example 1] 208.4 g of a terminal hydroxyl group-containing hydrogenated polybutadiene represented by the following formula (6) (GI-1000, manufactured by Nippon Soda Co., Ltd., catalog value of number average molecular weight (Mn): 1500, calculated repeating unit number n is about 25. The measured value of number average molecular weight (Mn) by GPC is 3100.), 12.73 g of maleic anhydride, and 0.002 g of tetra-n-butoxytitanium were placed in a 500 ml separable flask, and while stirring under a nitrogen flow, it was gradually heated to 200 °C and held until no distillate water came out. Then, after gradually reducing the pressure to 13 kPa, it was held for 30 minutes, cooled to room temperature, and Unsaturated polyester resin a of Preparation Example 1 was obtained. The number average molecular weight of Unsaturated polyester resin a was 6500.

[0116] [Chemical formula]

[0117] [Comparative Preparation Example 1] Instead of GI-1000, 208.4 g of a terminal hydroxyl group-containing hydrogenated polybutadiene represented by the above formula (6) (GI-2000, manufactured by Nippon Soda Co., Ltd., catalog value of number average molecular weight (Mn): 2000, calculated repeating unit number n is about 34. The measured value of number average molecular weight (Mn) by GPC is 4200.) was used, and Unsaturated polyester resin b of Comparative Preparation Example 1 was obtained in the same manner as in Preparation Example 1 except that the amount of maleic anhydride used was changed to 8.6 g. The number average molecular weight of Unsaturated polyester resin b was 8000.

[0118] [Comparative Preparation Example 2] Except for using 12.99 g of succinic anhydride instead of maleic anhydride, an unsaturated polyester resin c of Comparative Preparation Example 2 was obtained in the same manner as in Preparation Example 1. The number average molecular weight of the unsaturated polyester resin c was 6000.

[0119] Table 1 shows the compositions and the like of the unsaturated polyester resins a to c.

[0120]

Table 1

[0121] [Example 1] 3 g of the unsaturated polyester resin a of Preparation Example 1, 0.1 g of Perbutyl P (registered trademark, manufactured by NOF Corporation), and 7 g of maleimide compound a (phenylmethane maleimide, BMI-2300, manufactured by Daiwa Kasei Kogyo Co., Ltd.) were dissolved in 10 g of methyl ethyl ketone to obtain a 50% by mass solution 1 (resin composition). Then, a glass cloth E glass woven fabric (thickness: 95 μm, mass (areal density): 108 g / m 2 ) having a size of 3 cm × 10 cm in plan view was coated with the same mass of solution 1 as that of the glass cloth E glass woven fabric and spread uniformly. After being naturally dried for about one day and then dried in an explosion-proof dryer at 130 °C for 3 minutes, a laminate A of Example 1 was obtained by pressing at 200 °C and 0.6 MPa using a copper foil (manufactured by Mitsui Mining & Smelting Co., Ltd., 3EC-M2S-VLP, thickness 12 μm). The copper foil was laminated so that the roughened surface of the resin was in contact with the copper foil.

[0122] [Example 2] A laminate B of Example 2 was obtained in the same manner as in Example 1, except that the amount of the unsaturated polyester resin a of Preparation Example 1 used was changed to 4 g and the amount of the maleimide compound a used was changed to 6 g.

[0123] [Comparative Examples 1 and 2] The laminates C and D of Comparative Examples 1 and 2 were obtained in the same manner as in Example 1, except that the unsaturated polyester resins b and c of Comparative Preparation Examples 2 and 3 were used instead of the unsaturated polyester resin a of Preparation Example 1, respectively.

[0124] [Comparative Example 3] 3 g of the terminal hydroxyl group-containing hydrogenated polybutadiene represented by the above formula (6) (GI-1000, manufactured by Nippon Soda Co., Ltd., catalog value of number average molecular weight (Mn): 1500, calculated repeating unit number n is about 25. The measured value of number average molecular weight (Mn) by GPC is 3100.), 0.1 g of Perbutyl P (registered trademark, manufactured by NOF Corporation), and 7 g of maleimide compound a (phenylmethane maleimide, BMI-2300, manufactured by Daiwa Kasei Kogyo Co., Ltd.) were dissolved in 10 g of methyl ethyl ketone to obtain a 50% by mass solution 2 (resin composition). Thereafter, the laminate E of Comparative Example 3 was obtained in the same manner as in Example 1, except that solution 2 was used instead of solution 1.

[0125] [Reference Example 1] The laminate F of Reference Example 1 was obtained in the same manner as in Example 1, except that 3 g of the unsaturated polyester resin a of Preparation Example 1 was not used and the amount of maleimide compound a used was changed to 10 g.

[0126] [Performance Evaluation] The following evaluations were performed on the laminates of Examples 1 to 2, Comparative Examples 1 to 3, and Reference Example 1, respectively.

[0127] (Copper foil peel strength) Laminated body samples with a length of 16 cm and a width of 1 cm were cut out from each laminate. A cut with a width of 10 mm was made in the copper foil of each laminate sample, and the copper foil was peeled off. The end of the peeled copper foil was fixed, and each laminate sample was pulled in a direction perpendicular to it by about 3 cm in length, and the maximum value of the tensile strength at that time was taken as the copper foil peel strength. The measurement of the copper foil peel strength was performed using a Strograph EII-L (manufactured by Toyo Seiki Co., Ltd.) at a tensile speed of 5 cm / min.

[0128] (Moldability) The surface of the copper foil of each laminate sample was visually observed, and the evaluation was performed according to the following criteria respectively. A: No lines are formed on the surface of the copper foil, or the formed lines are less than 1 cm. C: The lines formed on the surface of the copper foil are 1 cm or more.

[0129] (Surface property) After physically peeling the copper foil of each laminate sample, the surface state was confirmed, and the evaluation was performed according to the following criteria respectively. A: There is no stickiness on the surface of the cured product of the resin composition. C: There is stickiness on the surface of the cured product of the resin composition.

[0130] Table 2 shows the evaluation results.

[0131]

Table 2

[0132] [Example 3] A laminate G of Example 3 was obtained in the same manner as in Example 1, except that maleimide compound b ((bis-(3-ethyl-5-methyl-4-maleimidophenyl)methane), BMI-70, manufactured by Kayaku Co., Ltd.) was used instead of maleimide compound a.

[0133] [Reference Example 2] A laminate H of Reference Example 2 was obtained in the same manner as in Example 1, except that 3 g of the unsaturated polyester resin a3 of Preparation Example 1 was not used and 10 g of maleimide compound b was used instead of maleimide compound a.

[0134] Table 3 shows the evaluation results.

Table 3

Claims

1. An unsaturated polyester resin comprising a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2).

2. 【Chemical 1】 (In the above formula (1), R 1 is a divalent linking group having one or more ethylenically unsaturated bonds.) [Chemical Formula 2] (In the above formula (2), R 2 and R 3 are each independently a linear or branched hydrocarbon linking group having 1 to 10 carbon atoms, and n is the number of repeating units.) The unsaturated polyester resin according to claim 1, wherein n in the structural unit represented by the formula (2) is 5 or more and 33 or less.

3. The unsaturated polyester resin according to claim 1, wherein the structural unit represented by the formula (1) is derived from at least one selected from the group consisting of unsaturated dicarboxylic acids, aromatic dicarboxylic acids, and acid anhydrides thereof.

4. The unsaturated polyester resin according to claim 1, wherein the structural unit represented by the formula (2) is derived from hydrogenated polybutadiene having terminal hydroxyl groups.

5. The unsaturated polyester resin according to claim 1, wherein the structural unit represented by the formula (1) is derived from at least one selected from the group consisting of maleic anhydride, maleic acid, fumaric acid, phthalic anhydride, and phthalic acid.

6. The unsaturated polyester resin according to claim 1, wherein the molar ratio of the structural unit represented by the formula (1) to the structural unit represented by the formula (2) is 0.50 or more and 5.0 or less.

7. The unsaturated polyester resin according to claim 1.

8. A cured product of the unsaturated polyester resin according to any one of claims 1 to 7.

9. A resin composition comprising the unsaturated polyester resin according to any one of claims 1 to 7.

10. The number average molecular weight is 5.00×10 2 or more and 3.00×10 4 or less, The resin composition according to claim 9, wherein the content of the unsaturated polyester resin is 0.50 part by mass or more with respect to 100 parts by mass of the resin component.

11. A method for producing an unsaturated polyester resin, comprising reacting a compound represented by the following formula (4) and / or a compound represented by the following formula (4') with a compound represented by the following formula (5).

12. The production method according to claim 11, wherein n in the compound represented by the formula (5) is 5 or more and 33 or less.

13. The production method according to claim 11, comprising reacting the compound represented by the formula (4) and / or the compound represented by the formula (4') with the compound represented by the formula (5) such that the molar ratio of the total amount of the compound represented by the formula (4) and the compound represented by the formula (4') to the compound represented by the formula (5) is 0.50 or more and 5.0 or less. ​ ​ ​ ​ [Chemical Formula 3] 【Chemical Formula 4】 (In the above formula (4), R 1 is a divalent linking group having one or more ethylenically unsaturated bonds, and R 3 and R 4 are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. In the above formula (4'), R 1 has the same meaning as R 1 in the above formula (4).) 【Chemical Formula 5】 (In the above formula (5), R 2 and R 3 are each independently a linear or branched hydrocarbon linking group having 1 to 10 carbon atoms, and R 5 and R 6 are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, and n is the number of repeating units.) ​ ​ ​ ​ ​ ​

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